Non-adiabatic molecular dynamics by accelerated semiclassical Monte Carlo.

Area of Science:

• Computational Chemistry
• Quantum Dynamics
• Molecular Modeling

Background:

• Non-adiabatic dynamics, involving transitions between electronic states, are vital for photo-physical processes like fluorescence and photoisomerization.
• Current simulation methods for non-adiabatic dynamics are often computationally expensive, complex, or rely on approximations that limit their applicability.
• The Semiclassical Monte Carlo (SCMC) method offers a balance between accuracy and efficiency but remains too slow for large molecular systems.

Purpose of the Study:

• To develop computationally efficient methods for simulating non-adiabatic dynamics.
• To improve the Semiclassical Monte Carlo (SCMC) algorithm for practical application to realistic molecular systems.

Main Methods:

• Development of two novel accelerated Semiclassical Monte Carlo (SCMC) algorithms: accelerated-SCMC and accelerated-SCMC with re-Gaussianization.
• Evaluation of the computational cost and accuracy of the new methods compared to standard SCMC and surface hopping schemes.

Main Results:

• The accelerated-SCMC methods reduce the computational cost of SCMC simulations by up to two orders of magnitude for specific systems.
• The new methods achieve computational efficiency comparable to widely used surface hopping schemes.
• The accuracy of the accelerated SCMC methods is largely preserved, with minimal loss compared to standard SCMC.

Conclusions:

• The developed accelerated-SCMC algorithms provide a significant advancement in simulating non-adiabatic dynamics.
• These methods offer a practical and accurate computational solution for studying complex molecular systems.
• The enhanced efficiency makes non-adiabatic dynamics simulations feasible for a broader range of scientific investigations.